PACE: Analysis of acute toxicity in PACE-B, an international phase III randomized controlled trial comparing stereotactic body radiotherapy (SBRT) to conventionally fractionated or moderately hypofractionated external beam radiotherapy (CFMHRT) for localized prostate cancer (LPCa).
2019; Lippincott Williams & Wilkins; Volume: 37; Issue: 7_suppl Linguagem: Inglês
10.1200/jco.2019.37.7_suppl.1
ISSN1527-7755
AutoresNicholas John Van As, Douglas Brand, Alison Tree, Peter Ostler, William Chu, Andrew Loblaw, Daniel Ford, Shaun Tolan, Suneil Jain, Alexander S. Martin, John Staffurth, Stephanie Brown, Stephanie Burnett, A. Duffton, Clare Griffin, Vicki Hinder, Kirsty Morrison, Olivia Naismith, Emma Hall,
Tópico(s)Advanced Radiotherapy Techniques
Resumo1 Background: External beam radiotherapy (EBRT) is a curative treatment for LPCa. Large randomised controlled trials (RCTs) have shown moderately hypofractionated regimens (2.5–3 Gy/fraction(f)) as non-inferior to conventionally fractionated regimens (2 Gy/f). PACE-B aims to demonstrate non-inferiority of SBRT compared to CFMHRT for biochemical or clinical failure. Compared to CFMHRT, SBRT reduces patient (pt) attendances but compressed overall treatment time may influence acute toxicity severity. Methods: PACE is a phase III open-label multiple-cohort RCT. Men with LPCa, stage T1-T2, ≤ Gleason 3 + 4, PSA ≤ 20 ng/mL, unsuitable for surgery or preferring EBRT, were eligible for the PACE-B cohort. Between 08/12-01/18, 874 pts (38 centres) were randomised (1:1) to SBRT or CFMHRT. SBRT dose was 36.25 Gy/5f in 1-2 weeks (wks), CFMHRT as 78 Gy/39f over 7.5 wks, or 62 Gy/20f in 4 wks. Androgen deprivation therapy was not permitted. Clinician reported acute toxicity was assessed at baseline, 2-weekly during CFMHRT and at 2, 4, 8 & 12 wks post-treatment. Key toxicity outcomes were worst grade 2+ Radiation Therapy Oncology Group (RTOG) genitourinary (GU) and gastrointestinal (GI) acute toxicities, compared by Chi-square test with alpha 0.05 divided between the two measures. Results: By per protocol analysis n=430 received CFMHRT, n=414 received SBRT. Key characteristics seen in the CFMHRT and SBRT groups respectively were: mean age: 69.5 vs 69.3 years; T-stage ≥T2b: 51.8% vs 56.6%; Gleason Score 3+4: 80.2% vs 85.0%; PSA 10-20 ng/mL: 30.9% vs 31.6%. RTOG G2+ toxicity was not significantly different for GI events (CMFHRT 52/430 (12.1%) vs SBRT 42/414 (10.1%), p=0.368), nor GU events (CFMHRT 117/430 (27.2%) vs SBRT 96/414 (23.2%), p=0.179). Conclusions: Despite an accelerated treatment schedule, RTOG assessments show similar rates of acute GI and GU toxicity for SBRT and CFHFRT. Pt follow-up in PACE-B continues and results of late toxicity and biochemical/clinical failure are awaited. Clinical trial information: NCT01584258.
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